U.S. patent number 6,976,437 [Application Number 10/368,284] was granted by the patent office on 2005-12-20 for blow molded pallet with inserts.
This patent grant is currently assigned to Poly-Flex, Inc.. Invention is credited to Robert J. Fisch, Floyd F. Markling, Amy R. Seibel, Randal P. Wiser.
United States Patent |
6,976,437 |
Fisch , et al. |
December 20, 2005 |
Blow molded pallet with inserts
Abstract
A pallet system includes a pallet body. The pallet body is
formed from a first, independently formed first portion and a
second blow molded second upper portion insert molded to the first
portion. The pallet body may have two to eight recesses for
forklift truck fork access. The second upper portion has a
generally rectangular surface for carrying loads. The portions may
have anti-skid properties, for example, a knurled topside surface
or rubber coated bottom. At least one foot is attached to the
second upper portion by insert molding. At least one runner may be
attached to each foot to form part of the first portion. At least
one stringer is attached to each runner to add further stability to
the pallet. The runners and feet have channels or protruding
members to effectively mate with the second upper portion. The
system may also have top cap and tie members to affix the cap to
one or more pallet bodies.
Inventors: |
Fisch; Robert J. (Elkhorn,
WI), Wiser; Randal P. (Delevan, WI), Seibel; Amy R.
(Mequon, WI), Markling; Floyd F. (Wiersdale, FL) |
Assignee: |
Poly-Flex, Inc. (Walworth,
WI)
|
Family
ID: |
32850143 |
Appl.
No.: |
10/368,284 |
Filed: |
February 17, 2003 |
Current U.S.
Class: |
108/57.25 |
Current CPC
Class: |
B29C
49/20 (20130101); B65D 19/0012 (20130101); B65D
19/0026 (20130101); B65D 19/0028 (20130101); B65D
19/0036 (20130101); B29C 2049/2017 (20130101); B29C
2049/206 (20130101); B29C 2791/001 (20130101); B29L
2031/7178 (20130101); B65D 2519/00034 (20130101); B65D
2519/00069 (20130101); B65D 2519/00104 (20130101); B65D
2519/00129 (20130101); B65D 2519/00134 (20130101); B65D
2519/00139 (20130101); B65D 2519/00208 (20130101); B65D
2519/00273 (20130101); B65D 2519/00278 (20130101); B65D
2519/00288 (20130101); B65D 2519/00293 (20130101); B65D
2519/00303 (20130101); B65D 2519/00318 (20130101); B65D
2519/00323 (20130101); B65D 2519/00333 (20130101); B65D
2519/00338 (20130101); B65D 2519/00358 (20130101); B65D
2519/00363 (20130101); B65D 2519/00373 (20130101); B65D
2519/00388 (20130101); B65D 2519/00407 (20130101); B65D
2519/00412 (20130101); B65D 2519/00432 (20130101); B65D
2519/00557 (20130101); B65D 2519/00567 (20130101); B65D
2519/00711 (20130101); B65D 2519/00835 (20130101); B65D
2519/0084 (20130101); B65D 2519/0094 (20130101); B65D
2519/00985 (20130101) |
Current International
Class: |
B65D 019/38 () |
Field of
Search: |
;108/57.25,57.26,57.27,57.28,51.11,56.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
SKIDMARX; Low Cost, Light Weight Recyclable Pallet Systems;
http://www.skidmarx.com/skidmarx.htm. .
BUCKHORN; The Best Usable Plastic Packaging Opportunities; 2002;
pp. 5-16, Form No. 401144 1/02 40M..
|
Primary Examiner: Chen; Jose V.
Attorney, Agent or Firm: Tschida; D L
Claims
What is claimed is:
1. A pallet comprising: a pallet stabilizing component including a
plurality of support portions and a plurality of attachment
portions; and a load bearing component having a hollow interior
cavity space defined between upper and lower surfaces and wherein
an attachment portion of said load bearing component is blow molded
to include a plurality of attachment surfaces having shapes that
are conformally bonded and interlocked in complementary mating
relation with each of said attachment portions and whereby said
pallet stabilizing component is integrated into said load bearing
component.
2. The pallet of claim 1 further comprising four recesses for
four-way access.
3. The pallet of claim 1 wherein the pallet stabilizing component
includes a plurality of runners.
4. The pallet as set forth in claim 1 wherein said pallet
stabilizing component includes a plurality of feet and wherein each
attachment surface is blow molded to conformally bond and interlock
with each of said plurality of feet.
5. The pallet as set forth in claim 1 wherein said plurality of
support portions comprise a plurality of runners and wherein each
runner includes a plurality of feet.
6. The pallet of claim 1 wherein the load bearing component
comprises a waffle configuration.
7. The pallet of claim 1 wherein the pallet stabilizing component
comprises a honeycomb configuration.
8. The pallet of claim 1 further comprising a recess for receiving
forks of a fork lift.
9. The pallet of claim 1 wherein an underside surface of the load
bearing component has pocket formed to provide anti-slip
properties.
10. The pallet of claim 1 wherein a bottom of the pallet
stabilizing component has pockets for varying the weight to
strength ratio.
11. The pallet of claim 1 wherein the load bearing component is a
first color; and wherein the pallet stabilizing component is a
second color.
12. The pallet of claim 1 wherein the pallet stabilizing component
is blow molded.
13. The pallet of claim 1 wherein said pallet stabilizing component
is comprised of at least one of the following materials: wood,
metal or plastic.
14. A method of blow molding a pallet comprising the steps of a)
forming a pallet stabilizing component having a support portion and
an attachment portion; b) inserting the pallet stabilizing
component into a mold and exposing said attachment portion in a
mold cavity; and c) blow molding a load bearing component having a
hollow interior cavity space to conformally bond in interlocking,
complementary relation with said attachment portion, whereby said
pallet stabilizing portion and load bearing portion are integrated
to one another to form a pallet.
15. The method of claim 14 wherein said pallet stabilizing
component comprises first and second runners, wherein said first
and second runners each include a plurality of feet, and wherein
said first and second runners further include a protruding
attachment member.
16. The method of claim 15 wherein at least one protruding member
comprises a flange.
17. The method of claim 14 wherein said attachment portion
comprises a cavity.
18. A method of forming a plastic pallet comprising the steps of:
a) forming first and second plastic runners, wherein each of said
first and second runners has a support portion and an attachment
portion; b) inserting the first and second runners into a mold and
exposing each attachment portion in a mold cavity; c) blow molding
a load bearing component having a hollow interior cavity to
conformally engage and bond to each attachment portion to integrate
said first and second runners to said load bearing component and
form a pallet; d) ejecting the pallet from the mold; and e)
allowing the pallet to cool.
19. The method of claim 18 further comprising, between steps b) and
c), the step of holding at least one of said first and second
runners in place by a clamp during the blow molding of the load
bearing component.
20. The method of claim 18 further comprising the step of inserting
a reinforcing member into said mold during the blow molding of the
load bearing component, whereby the reinforcing member becomes
encased in said pallet.
21. The method of claim 18 further comprising the step of inserting
a reinforcing member into said load bearing component as said
pallet cools, whereby surfaces of said load bearing component
shrink around said reinforcing member.
22. The method of claim 18 wherein said first and second runners
each include a plurality of feet and wherein said attachment
portion comprises a plurality of attachment surfaces including
protrusions and/or recesses at each of said plurality of feet and
wherein said load bearing component is molded to interlock in
complementary engagement with said attachment surfaces.
23. The method of claim 18 wherein a plurality of feet extend from
said first and second runners, wherein each of said plurality of
feet includes a protruding member, and wherein each protruding
member is conformally interlocked into the load bearing
component.
24. The method of claim 23 wherein at least one protruding member
comprises a flange.
25. The method of claim 24 wherein at least one flange includes a
rib.
26. The method of claim 24 wherein at least one flange includes a
groove.
27. A pallet comprising: a pallet stabilizing component including a
plurality of runners and wherein a plurality of feet project from
said plurality of runners and further including a plurality
attachment members; and a load bearing component having a hollow
interior cavity space defined between upper and lower surfaces and
wherein an attachment portion of said load bearing component is
blow molded to bond to and define a shape that conformally
interlocks in complementary relation with each attachment member
and whereby said plurality of runners and feet are integrated into
said load bearing component.
28. The pallet of claim 27 further comprising four recesses for
four-way access.
29. A pallet comprising: a pallet stabilizing component comprising
a plurality of feet and wherein said plurality of feet each include
a protruding member; and a load bearing component having a hollow
interior cavity space defined between upper and lower surfaces and
wherein a plurality of attachment surfaces of said load bearing
component are blow molded to define a complementary shape that
conformally interlocks with and bonds to each protruding member and
whereby said plurality of feet are integrated into said load
bearing component to form a pallet.
30. The pallet of claim 29 wherein said protruding member comprises
a flange.
31. The pallet of claim 30 wherein at least one flange includes a
groove and wherein said top load bearing component includes a lip
that interlocks with said groove.
32. The pallet of claim 29 wherein said plurality of feet extend
from a plurality of runners.
33. The pallet of claim 29 wherein said plurality of feet extend
from a plurality of runners, wherein said protruding member
comprises a flange, and wherein said load bearing component
conformally encases a substantial portion of each flange.
34. A method of blow molding a pallet comprising the steps of a)
forming a pallet stabilizing component having a support portion and
an attachment portion; b) inserting the pallet stabilizing
component into a mold and exposing said attachment portion in a
mold cavity; and c) blow molding a load bearing component having a
hollow interior cavity space and wherein a portion said load
bearing component forms a complementary shape that interlocks with
said attachment portion, whereby said pallet stabilizing component
and said load bearing component are integrated to one another to
form a pallet.
35. The method of claim 34 wherein said attachment portion
comprises a protruding member.
36. The method of claim 35 wherein said protruding member includes
a groove.
37. The method of claim 34 wherein said attachment portion
comprises a flange.
38. A method of blow molding a pallet comprising the steps of a)
forming a pallet stabilizing component having a support portion and
an attachment portion including a recess; b) inserting the pallet
stabilizing component into a mold and exposing said attachment
portion in a mold cavity; and c) blow molding a load bearing
component having a hollow interior cavity space to conformally bond
and interlock in complementary relation with said recess portion,
whereby said pallet stabilizing component and load bearing
component are integrated to one another to form a pallet.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to the field of plastics.
More particularly, the present invention relates to a pallet system
and a pallet apparatus and a method of pallet manufacturing.
Specifically, one preferred embodiment of the present invention
relates to blow molding a first pallet piece and then inserting it
into another mold to join it to a second blow molded pallet
piece.
2. Discussion of the Related Art
Pallets are used for transporting and storing various types of
cargo throughout the world. Therefore, it is important for a pallet
to be lightweight, compact and strong. Traditionally pallets were
made of wood, however, plastic pallets are now being used with
increased frequency as they are lightweight, generally stronger, do
not absorb moisture, and they can be cleaned and disinfected which
is important in particular for the food industry. One disadvantage
of plastic pallets is that they tend to break up with continued use
over time. Therefore, for these and other various reasons it is
important that plastic pallets be reinforced by a variety of
means.
The below-referenced U.S. patents disclose embodiments that were at
least in-part satisfactory for the purposes for which they were
intended. The disclosures of all the below-referenced prior United
States patents, in their entireties, are hereby expressly
incorporated by reference into the present application for purposes
including, but not limited to, indicating the background of the
present invention and illustrating the state of the art.
U.S. Pat. No. 5,417,167 discloses a plastic shipping pallet of the
type usually manufactured from wood which is made of hollow plastic
stringers and deck boards. The stringers and deck boards are made
of plastic materials that may be either virgin plastic, recycled
plastics or mixes. The stringers and deck boards are hollow but
have closed ends to prevent entry of dirt, fluids, insects and
vermin. The stringers and deck boards may be made in a blow molding
process or using continuous extrusion and molding processes similar
to that used in the manufacture of corrugated pipe. Various
connection configurations for affixing the deck boards to the
stringers are described including fixation by screws as well as
interlocking connections between the plastic parts themselves and
the use of separate interlocking components which engage the deck
board and stringers.
U.S. Pat. No. 5,845,588 discloses a pallet fabricated of a
thermoplastic material which is produced by joining together
individually fabricated structural components, each of which is
individually thermoformed from an extruded plastic parison of a
multilayer structure. The structural components include a deck in
the form of a continuous sheet with longitudinal and transverse
sides, one or more upper runner components fastened by their top
side to the bottom of the deck, each of which includes a cross
member with downward-facing posts, and one or more lower runner
components, each of which includes a cross member with
upward-facing posts and which is fastened by the tops of its posts
to the bottoms of matching posts on the corresponding upper runner
components.
U.S. Pat. No. 5,868,080 discloses a reinforced plastic pallet
construction and assembly method wherein multiple reinforcing bars
are employed. At least some of the reinforcing bars have an exposed
surface at a topside surface, underneath surface or underside
surface of the pallet. In addition to functioning as a reinforcing
member, the exposed surfaces of the reinforcing bars comprise an
anti-skid surface for maintaining positioning of payload on the
pallet or facilitating transport of the pallet, e.g., via a
forklift or automated transport system. Various techniques for
retaining the reinforcing bars within channels formed in the
plastic pallet body are described. The reinforcing bars preferably
comprise composite structural members of fiberglass reinforced
plastic fabricated from a pultrusion process.
U.S. Pat. No. 6,209,464 discloses a pallet that includes a
rectangular support deck having a substantially planar upper
supporting surface including a plurality of channels formed therein
and extending across the pallet. The deck includes support members
extending from an underside of the deck that nest in recesses
formed in the upper surface of the deck. An alignment portion is
formed at a center point along the first edge of the deck and a
second alignment portion is formed at a center point of an opposed
edge of the deck. The alignment portion includes angled sides for
receiving a tapered member of a complementary device.
SUMMARY AND OBJECTS OF THE INVENTION
It is one object of the present invention to provide a light-weight
and compact yet more durable pallet. It is another object of the
invention to use 100% recycled plastic in construction of the
pallet to provide a cleaner environment. It is still another object
of the invention to have a pallet with improved weight to strength
ratio. It is yet another object to provide a pallet that is
stackable and nestable with other pallets. It another object of the
invention to provide a pallet of varying colors that is inexpensive
to produce and easy to manufacture using largely recycled
materials.
Another object of the invention is to provide a pallet that is more
ruggedized and reliable, thereby decreasing down time and operating
costs. Another object of the invention is to provide a pallet that
has one or more of the characteristics discussed above but which is
relatively easy to assemble using a minimum of equipment. Another
object of the invention is to provide a process of manufacture that
is predictable and reproducible, thereby decreasing variance and
operating costs. Another object of the invention is to provide a
method that has one or more of the characteristics discussed above
but which is relatively simple to setup and operate using
relatively low skilled workers.
In accordance with one aspect of the invention, the inventive
pallet system has a pallet body which has a separately formed lower
or pallet stabilizing portion (i.e., a first portion) and a
separately blow molded upper or load bearing portion (i.e., a
second portion) connected to the first portion. The pallet body
preferably has four recesses for four-way fork access. The second
or upper portion may have a non-slip topside surface, e.g., a
knurled surface. The first portion is preferably made up of at
least one foot which is attached to the second portion by insert
molding, one rail or runner attached to the foot, and one stringer
attached to the runner. In one embodiment, the first portion
includes a plurality of feet secondly molded into the second or
load bearing portion. The runners preferably have a ridge or
protruding member for engagement with the foot, and the foot
preferably includes a channel for engagement with the load bearing
portion. The load bearing and pallet stabilizing portions may be
pocketed, have waffle configuration, or honeycomb configuration for
added weight to strength ratio. The pockets have at least one of
the following shapes: triangular, circular, square, oval,
rectangular, hexagonal, and octagonal. The second or load carrying
portion may also contain at least one cavity and/or perimeter lip
on a topside surface for receiving a pallet stabilizing surface of
another pallet in a nesting or stacking arrangement. The feet and
the runners are shaped like at least one of the following:
triangle, square, rectangle, parallelogram, and trapezoid.
Alternatively, the foot is at least frustoconical or pyramidal
shaped. Ribs may also provide attachment of the second upper
portion to the runner.
Other features of the upper or load bearing portion include an end
cap to cover the fork receiving recesses, and a cavity cover for
covering the nesting cavities when not in use. The pallet further
preferably has at least one handle hole for ease of carrying by a
user. The pallet and all of its parts may be constructed of
recycled HDPE plastic of a wide variety of colors.
The pallet system may further include a load identification system
including at least one of the following: bar coding, hot stamping,
molding in a logo, affixing a card holder, and tagging with tape, a
top cap, and tie members for securing the cap to at least one
pallet body.
The pallet system may further include a load identification system
including at least one of the following bar coding, hot stamping,
molding in a logo, affixing a card holder, and tagging with tape, a
top cap, and tie members for securing the cap to at least one
pallet body.
In accordance with another aspect of the invention, the inventive
method of manufacturing a pallet preferably includes the steps of
inserting the pallet stabilizing portion into a mold (such as a
plastic, metal or wood rod) and then blow molding around the insert
a load bearing portion. In one embodiment, the method of forming a
plastic pallet preferably has the steps of: a) forming a first
runner; b) forming a second runner; c) forming a third runner; d)
inserting the runners into a mold; e) blow molding a load bearing
portion in a manner which engages the runners to form a pallet; f)
ejecting the pallet from the mold; g) allowing the pallet to cool
before stacking them. The runners may be put into the mold by an
automated arm and held in place by a spring biased or other type of
clamp during the blow molding of the load bearing portion.
Reinforcing members may also be inserted during this process. The
members are preferably rolled steel rods that are inserted into
channels in the second portion while this portion is cooling.
These and other aspects and objects of the present invention will
be better appreciated and understood when considered in conjunction
with the following description and the accompanying drawings. It
should be understood, however, that the following description,
while indicating preferred embodiments of the present invention, is
given by way of illustration and not of limitation. Many changes
and modifications may be made within the scope of the present
invention without departing from the spirit thereof, and the
invention includes all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
A clear conception of the advantages and features constituting the
present invention, and of the construction and operation of typical
mechanisms provided with the present invention, will become more
readily apparent by referring to the exemplary, and therefore
non-limiting, embodiments illustrated in the drawings accompanying
and forming a part of this specification, wherein like reference
numerals designate the same elements in the several views, and in
which:
FIG. 1 is a perspective underside view of one embodiment of the
pallet system of the present invention;
FIG. 2 is a perspective view of the pallet runner shown in FIG. 1
of the present invention;
FIG. 3 is a perspective topside view of FIG. 1 of the present
invention;
FIG. 4 is a perspective view of another embodiment of the present
invention;
FIG. 5 is a side view of another embodiment of the present
invention;
FIG. 6 is a side view of another embodiment of the present
invention;
FIG. 7 is a side view of the embodiment of the present
invention;
FIG. 8 is a perspective underside view of another embodiment of the
pallet of the present invention;
FIG. 9 is a perspective view of the pallet runner shown in FIG. 8
of the present invention;
FIG. 10 is a perspective topside view of FIG. 8 of the present
invention;
FIG. 11 is a perspective topside view of another embodiment of the
present invention;
FIG. 12 is a perspective underside view of FIG. 11 of the present
invention;
FIG. 13 is a perspective view of another embodiment of the present
invention;
FIG. 14 is a perspective underside view of another embodiment of
the present invention;
FIG. 15 is a perspective underside view of another embodiment (like
FIG. 8) of the present invention including stringers;
FIG. 16 a cutaway view along A'--A' of FIG. 1 of the present
invention;
FIG. 17 is a cutaway view of the embodiment of FIG. 1 shown in a
mold;
FIGS. 18-20 are various perspective views of another embodiment of
the pallet runner of the present invention;
FIG. 21 is a cutaway view (along B'--B' of the runner of FIG. 20)
of still another embodiment of the present invention showing the
incorporation of the runner shown in FIGS. 18-20;
FIGS. 22-26 depict cutaway view of other embodiments of the present
invention showing the connection of the lower portion to the upper
portion.
FIG. 27 is a perspective view of another embodiment of the present
invention;
FIG. 28 is a perspective underside view of another embodiment of
the present invention;
FIG. 29 is a perspective topside view of the pallet system shown in
FIG. 28;
FIG. 30 shows one embodiment a foot of the pallet system shown in
FIGS. 28-29;
FIG. 31 is a cutaway view along C'--C' of the embodiment of FIG.
29;
FIG. 32 is a cutaway view of two pallets like the one shown in FIG.
28 nested and stacked;
FIG. 33 is a perspective topside view of another embodiment of the
present invention;
FIG. 33A is a cutaway view along D'--D' of the embodiment shown in
FIG. 33;
FIG. 34 is a cutaway view along D'--D' of the embodiment shown in
FIG. 33;
FIG. 35 is a perspective view of another embodiment of the pallet
system present invention;
FIG. 35 is a perspective view of another embodiment of the pallet
system present invention;
FIG. 36 is a perspective view of a pallet mold and one embodiment
of the pallet system present invention; and
FIG. 37 is a flowchart illustrating the inventive blow molding
method.
FIG. 38 depicts a cross section view taken along section line E--E
of FIG. 12 showing the connection of feet to the upper portion.
FIGS. 39-42 depict cross section views taken along section line
F--F of FIG. 12 showing alternative connections of feet to the
upper portion.
In describing the preferred embodiment of the invention, which is
illustrated in the drawings, specific terminology will be resorted
to for the sake of clarity. However, it is not intended that the
invention be limited to the specific terms so selected and it is to
be understood that each specific term includes all technical
equivalents which operate in a similar manner to accomplish a
similar purpose. For example, the word "connected" or terms similar
thereto are often used. They are not limited to direct connection
but include connection through other elements where such connection
is recognized as being equivalent by those skilled in the art.
DETAILED DESCRIPTION
The present invention and the various features and advantageous
details thereof are explained more fully with reference to the
non-limiting embodiments described in detail in the following
description.
1. Preferred Embodiments
As shown in FIG. 1, pallet system 5 contains a body 10 which
includes an upper or load bearing component or portion 15 and a
lower or pallet stabilizing component or portion 20. The upper or
second portion 15 preferably includes topside surface 18 and
underside surface 19 on a top deck 21. In the lower or first
portion 20 may include several feet and/or rails or runners
attached thereto. For example, at each of the four corners a first
foot 35, a second foot 38, a third foot 39, and a fourth foot 40
may be either integrally or separately formed into the top deck 21.
In the preferred embodiment at least two rails, a first rail or
runner 25 and a second rail or runner 30, are then either
integrally or separately connected to the feet 35, 38, 39 and 40.
Additional rails or runners may be added for additional strength
and additional feet may be added as well (see, e.g., FIGS. 5-10).
One runner is typically 48 inches long. As shown in FIGS. 8-10,
additional feet 43, 44, 46 of different sizes may also be
present.
The rails or runners 25, 30 and feet may be separately formed as
individual parts (see FIG. 2) or may be molded into an upper half
47 and a lower half 48 as shown in the embodiment at FIG. 4. These
pieces are separately blow-molded then they may be insert molded to
join them to the opposite half. Alternatively, the feet and rails
may be formed by injection molding, rotomolding, winding,
thermoforming, etc. In this embodiment, the feet 35, 40 are formed
from first foot portion 35a, 40a and second foot portion 35b, 40b.
The first portions 35a and 40a are preferably connected by an upper
rail 49. Although not shown, a similar structure may be utilized
for other feet and runners. For example, if the upper half 47 is
first blow molded, it may be inserted into another mold and the
bottom half 48 is then newly blow molded in such a way so that the
two pieces 47, 48 become connected through the blow molding
process. In the same way, upper half 47 and lower half 48 shown in
FIG. 4 may be blow molded to the top deck 21. Alternatively, upper
half 47 may actually be initially integrally blow molded as part of
the deck 21. In this embodiment the half 47 may be in the lower
half of the part mold while the deck may be in the upper half of
the part mold. After the pieces have been combined through the
insert molding process, they form the body 10 of the pallet system
5. For example, once the upper half 47 and lower half 48 are blow
molded together, the combined pieces may be inserted into a new
mold and the second upper portion 15 may be blow molded around
them.
As shown in the embodiments shown in FIGS. 5, 6 and 7, there are
many variations on the pallet foot and rail structure. In addition,
another foot 42 or series of feet may be added to provide more
structural rigidity. For example, a bottom deck 22 may be
separately or integrally blow molded into the top deck and rails to
create the embodiment shown in FIG. 5. Alternatively, it is
possible that a plurality of feet 35, 40, 42 are inserted into a
mold and the top deck 21 will be blow molded around them as shown
in the embodiment in FIG. 6. Also possible is the embodiment shown
in FIG. 7 in which the triangular-shaped feet 35, 40, 42 are
separately blow molded and then a top deck 21 with feet is blow
molded around them, totally encapsulating the first molded feet
through the insert molding process.
It will be apparent to one of ordinary skill in the art that the
addition of feet and/or rails will further make the pallet 5
structure stronger. Thus, the embodiments shown in FIGS. 8-10 and
11-12 have nine feet and three runners. The rails 25, 30 and 32 are
incorporated into the upper or second portion 15 in FIGS. 8-10; and
each of the feet 35, 40 and 42 are separately incorporated in
similar fashions into the second portion 15 in FIGS. 11 and 12.
Alternative, exemplary molded couplings of the feet 35, 40 and 42
to the second portion 15 are depicted in FIGS. 38-42 in regard to
section lines E--E and F--F at FIG. 12. The molded couplings shown
at FIGS. 38-42 are similar to the molded couplings of the rail
portions 25, 30 and 32 shown at FIGS. 16 and 21-24.
As shown in FIG. 11, this embodiment preferably also has first
cavity 50, a second cavity 52, and a third cavity 55 to receive the
runners and/or feet when similar pallets 5 must be stacked for
storage. The depths of the cavities may vary depending on a variety
of factors such as thickness of the plastic and the dimensions of
the feet and/or runners.
The embodiment in FIG. 11 is known as a four way pallet because the
forks (not shown) of a fork lift (not shown) can be inserted into
the pallet in four different directions A, B, C, D. The pallet
preferably, as shown in FIG. 11, has recesses for receiving the
forks (60, 61, 62, 63, 64, 65, 66 and 67). The recesses 60-67 may
vary in depth and width depending on the type of pallets and may
also vary in number. For example, like in FIG. 1, in the embodiment
shown in FIG. 11 there are four recesses for the fork to enter in
this four-way pallet. Alternatively, pallet 5 may be a two-way
pallet as shown in FIG. 13 and thus it will have fewer
recesses.
As shown in FIGS. 12 and 13, pockets may be incorporated into the
design of the second or upper portion 15 and the first or lower
portion 20 to add strength and/or reduce weight. Such honeycomb or
waffle designs are often used when molding plastics. The pockets 70
may vary in dimensions and shape (e.g., triangles 70a or circles
70b). The pockets 72 on the lower portion 20 may also vary in
dimension and shape. The embodiment shown in FIG. 12, the pockets
72 may also serve to give the lower portion 20 an anti-skid
underside surface 75 so the pallet 5 does not slip off the forks.
However, this may also be done by merely the addition of knobs,
knurling, a rubberized coating and/or rubber grommets. The topside
surface (not shown) of the broken portion may also be pocketed. As
shown in the embodiment in FIG. 13, at least one, here two, metal
rods 78a, 78b may be insert molded into the pallet 5. One way of
doing this is by laying the rods into the mold and then blow
molding the pallet around them. Another way is to push these rods
78a, 78b in prior to the second portion's cooling. These
reinforcing rods 78a, 78b may also be constructed of wood or
plastic.
In the embodiments shown in FIGS. 14-15, at least one stringer
(e.g., 82) may be attached to the rails 25, 30, 32 to add
additional strength and stability to the pallet 5. In the
embodiment shown in FIG. 14, a first stringer 80, a second stringer
82, and a third stringer 83 connect to the rails 25, 30, and 32.
Again, the insert blow molding process can be used to connect the
stringers 80, 82 and 83 to the rails 25, 30, 32. Alternatively, a
post molding process may be used where the plastic or metal
stringer is inserted prior to the runners cooling.
As shown in FIGS. 16-21, the second portion 15 and/or first portion
20 may have either ribs 85 or protruding members, such as ridges or
flanges, 90 and channels 88 or holes 92 to engage each other during
the insert blow molding process. For example in FIG. 16, the second
or upper portion 15 contains channels 88, 88a, 88b, which are
engaged by protruding ridges 90 in the runner 25. Kiss off 84 helps
to further connect runner 25 to the top deck 21 as the runner's
crown 87 is pressed against the kiss off 84 within the first mold
half 81a and the second mold half 81b (see, e.g. FIG. 17). This
also helps to strengthen that point.
In FIGS. 18-21, protruding members or flanges 90 and ribs 85 are
received in hole 92 and channels 88, respectively. In this
embodiment, first the rail 30, ribs 85, and protruding members 90
are blow molded. Then they are set and appropriately exposed into a
cavity in a mold for a second or upper portion 15 to be insert blow
molded into connection with the second portion 15. A lip 89 and
groove 91 may also be employed as well. This deep draw molding
process strengthens the connection between the portions 15, 20.
As shown in FIG. 27, this embodiment has holes or recesses bore
through rectangular-shaped runners. The recesses are for receiving
the lifting tines of a forklift. When not in use, an end cap 95 may
be used to block the recesses 62-65 in the first portion 20. The
end cap 95 may limit entry on one or more sides of the pallet 5.
This may keep vermin out from underneath the pallet and/or limit
access by the forks of the forklift. In the embodiment shown in
FIG. 27, one or more cavity covers 100 may also be employed to
cover the cavities 52-55 on the second upper portion 15. As
indicated previously, these cavities normally receive a foot (not
shown) and/or a runner (not shown) of another pallet while nested.
Cavity covers may be used to also keep out vermin or other
materials and provide further stability to the top deck 21 of the
pallet. These covers (100) are generally flush with the topside
surface 18 so that loads do not get hung up. A recess and a lip may
be added to the cover and the cavity for a tighter fit. A handle
hole 105 may also be provided in at least one or more positions on
the pallet 5 to allow for easy handling and caring by a warehouse
worker. It is important to note that all the various holes, recess,
and cavities can be configured and arranged in a blow-molded
plastic pallet to decrease weight and increase strength.
FIGS. 29-32, show another more light weight embodiment of the blow
molded pallet system of the present invention. Again this pallet
system 305, has a body 310 including a lower or first portion 320
and upper or second portion 315. A deck 321 is on the top of the
second portion 315 and has a topside surface 318 and an underside
surface 319. As best shown in FIG. 30, this embodiment preferably
has individual hollow feet 335 which collectively form the first or
lower portion 320. As shown in FIG. 31, a deep draw blow molding
process may also be used to manufacture this embodiment. Again the
deep draw process incorporates the first portion 320 into the
second portion 315. This embodiment also allows for interlocking of
the protruding members 390 into holes 392. FIG. 32 shows how
several pallets, e.g., 305A and 305B of this type can be nested and
stacked together as the feet, e.g., 335A, 335B of the different
pallets 305A, 305B fit into each other.
FIGS. 33, 33A, 34 show an embodiment of another lighter weight
(e.g., less than 25 pounds) blow molded pallet system 405. This
pallet is preferably 40 inches wide, 48 inches long, and 4.5 inches
high. A pallet body 410 of the pallet system 405 may be blow molded
as a single piece and then an insert, e.g., a tube or rod 413 may
be inserted into the body 410 along a channel 416 after the molding
is complete. This is sometimes referred to as post molding. The
insert is preferably about 40 inches long and is fabricated
separately from plastic, metal or, wood. Alternatively, the insert
may be placed into the pallet body mold and the body is then blow
molded around it. One or more inserts may be used to increase the
strength of the pallet system. If the insert 413 is not plastic,
the insert should be removed before the pallet body is ground up
during the recycling process. As shown in FIG. 33A, one or more
kiss offs 384 may be incorporated in the pallet body 310 design to
add strength and reduce weight.
FIG. 35 shows stacked pallets nested and tied together with a strap
or tie 110 and a top cap 115. The top cap 115 preferably has at
least one metal reinforcing member 120 insert molded therein to
retain the tie 110. One or more pallets may have a load
identification system 125 as shown. FIG. 35 shows nested or stacked
pallets 5 with a perimeter lip 130. Foot 38 engages lip 130. The
tie 110 preferably is inserted through a hole found in the pallet
body deck (see FIG. 1).
Suitable materials for producing the inventive plastic pallet
include virgin or recycled polyolefins, polyethylene (PE),
polyvinyl chloride (PVC), acrylonitrile butadiene, styrene (ABS)
plastics, polypropylene, polyamides (PA), and polycarbonates (PC)
of one or more colors. The preferred embodiments are made of 100%
reground and recycled ultrahigh molecular weight high-density
polyethylene (HDPE-UHMW). Polypropylene homopolymer, or
polypropylene block copolymer may also be used for the various
parts of the pallet body. A suitable friction material may be
selected from polyolefins containing materials like LLDPE, TPE,
EVA, EEA and the like to stop things from sliding off the topside
surface 18 of the pallet or to further add friction to the
underside of the first portion of the pallet.
2. In Use and Operation
As indicated above, in the preferred embodiment there may be one or
more molds which independently and separately form (e.g.,
blow-mold) feet, runners and stringers. As shown in FIG. 36, there
is also preferably a mold 81 having two halves 81a and 81b which
separately blow molds a second or upper portion, and a first
portion. In the preferred embodiment, the second upper portion and
first portion molds have a position for receiving feet, runners 25,
30, and/or stringers. Typically, each mold is constructed of a
right half 81a and left half 81b.
As illustrated in FIG. 37, the separately formed 200 pieces (e.g.,
feet, runners, etc.) are then inserted 210 into the deck portion
mold and the deck portion is blow molded into or around the feet,
stringers, and/or the rails 220. In one embodiment, gravity holds
the inserts (e.g., the feet, runners, rods and stringers, etc.) in
place during the blow molding of the deck. In another embodiment,
pins that may be tensioned or spring biased hold the feet,
stringers, and/or runners in place in the deck mold. Because the
insert molding process adds steps and time to the molding of the
pallet, automating the steps can help reduce the impact of these
factors. Also, automation increases reproducibility and thus
quality control.
After the pallet is completely formed, it is ejected 230 from the
mold and allowed to cool 240. In one preferred embodiment, the mold
for the deck has the flexibility to receive either one or a
plurality of rails and/or feet depending on the type of pallet
requested by the customer. For example, Customer A1 may only want a
pallet with a top deck, four feet, and a bottom deck, while
Customer B2 may want a pallet with a top deck, six feet, and three
runners. These first portion pieces may all be first independently
molded and then inserted into a larger mold so that the inserts may
be blow molded together with the deck portion to form the complete
pallet end product requested by the customer. Alternatively, for
example, a blow molded bottom deck may be added later while still
warm by affixing it to the feet by some means such as an adhesive,
a channel/protruding member combination, a screw/fastener or some
other means.
The individual components described herein need not necessarily be
formed in the disclosed shapes, or assembled in the disclosed
configuration, but could be provided in virtually any shape, and
assembled in virtually any configuration. Further, although the
feet and runners are described herein as physically separate
modules, it will be manifest that it may be more fully integrated
into the deck portions. Furthermore, all the disclosed features of
each disclosed embodiment can be combined with, or substituted for,
the disclosed features of every other disclosed embodiment except
where such features are mutually exclusive. Finally, it is intended
that the appended claims cover all such additions, modifications
and rearrangements. Expedient embodiments of the present invention
are differentiated by the appended subclaims.
* * * * *
References